Nanoimprint technology in which a resin material coated on a substrate is embossed with a recess-protrusion pattern in tens of nanometers to hundreds of nanometers of a mold by pressing the two together has attracted attention recently. Applications of nanoimprint technology to optical materials, finer ICs, substrates for clinical laboratory test, and the like are now being developed and researched. Nanoimprint technology advantageously allows a component with a variety of characteristics to be produced at low costs as compared with conventional pattern-forming processes involving lithography and etching. This is because nanoimprinters have a simpler configuration and are less expensive than conventional apparatuses and further because it takes a short time to mass-produce components with the same shape.
Thermal nanoimprint and UV nanoimprint are known as nanoimprint technology. According to UV nanoimprint, for example, a mold with a nanosized recess-protrusion pattern is pressed against a UV-curable resin thin film formed on a transparent substrate, and the film is irradiated with UV rays, thereby producing a thin film with nanostructures on the transparent substrate. According to thermal nanoimprint, for example, a transparent substrate and a mold that are heated to the softening temperature of the transparent substrate or high are pressed against each other, thereby forming nanostructures (recesses and protrusions) on the transparent substrate. In a study, flat molds and batch process are commonly employed in the UV nanoimprint and the thermal nanoimprint.
With respect to technologies employing a batch process for forming nanostructures, for example, Patent document 7 discloses photo nanoimprint including pressing a mold into a photosensitive dry film and photoirradiation of the film.
In order to mass-produce thin films with nanostructures at low costs by nanoimprint technology, a roll-to-roll process is preferable to the batch process. The roll-to-roll process using a mold roller allows continuous production of the film with nanostructures.
With respect to nanoimprint technology involving the roll-to-roll process, for example, Patent Document 5 discloses that a pattern of a small mold roller is transferred onto a large mold roller while the pattern is extended by moving the small mold roller.
With respect to rollers used in the roll-to-roll process in technologies other than nanoimprint technology, for example, Patent Documents 6 discloses a method of producing a roller with a recess-protrusion pattern directly formed thereon.
Patent Document 1 discloses moth-eye structure(s) known as one type of the nanostructures in optical materials (optical elements). The moth-eye structures include, for example, nanosized corn-shaped protrusions formed on a transparent substrate surface. According to optical materials with the moth-eye structures, a reflected light amount can be dramatically decreased because a refractive index continuously changes from air to a transparent substrate and so incident light does not recognize the surface of the transparent substrate as an optical surface. In view of this, for example, Patent Documents 2 to 4 disclose, as a technology of producing optical materials with nanostructures, a method of using an aluminum substrate having a surface with nanosized cavities formed thereon by anodizing. According to this method involving anodizing, for example, nanosized cavities can be formed on a columnar mold roller surface in a random placement and in a uniform distribution, and therefore seamless nanostructures needed for continuous production can be formed on the surface.    [Patent Document 1]
Japanese Kokai Publication No. 2001-264520    [Patent Document 2]
Japanese Kohyo Publication No. 2003-531962    [Patent Document 3]
Japanese Kokai Publication No. 2003-43203    [Patent Document 4]
Japanese Kokai Publication No. 2005-156695    [Patent Document 5]
Japanese Kokai Publication No. 2007-203576    [Patent Document 6]
Japanese Kokai Publication No. 2005-144698    [Patent Document 7]
Japanese Kokai Publication No. 2007-73696